Rafting by Five Phyla on Man-made Flotsam in the Southern Ocean

Q: Why was the Southern Ocean considered protected from rafting organisms?

Freezing sea-surface temperatures were thought to hinder colonization and survival of animals rafting on floating debris.

Q: What was found on the plastic debris washed ashore on Adelaide Island?

A positively buoyant plastic packaging band hosted multiple taxa, including bryozoans, demosponges, polychaetes, a hydroid, and a small gastropod.

Q: What does the study suggest about animal transport between the Southern Ocean and other regions?

The presence of endemic Southern Ocean species on long-floating plastic indicates that such debris can carry diverse organisms, potentially allowing exotic species exchange into or out of the region.

Aug 28, 2026

Uploaded by Jacob

Marine litter has rapidly increased across northern oceans and is expanding even on remote Southern Ocean islands. The Southern Ocean was previously considered protected from rafting organisms by freezing sea-surface temperatures. The study reports an animal assemblage attached to a plastic band washed ashore on Adelaide Island, Antarctic Peninsula, where buoyancy allowed long afloat duration. At least 10 species from five phyla were identified, including endemic Southern Ocean taxa, indicating that diverse organisms can survive, grow, and potentially alter community exchange.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages3

Reading Time8 min

AccessFree to download

Abstract

Introduction

Debris Analysis

| Vol. 262: 289–291, 2003 | MARINE ECOLOGY PROGRESS SERIES
Mar Ecol Prog Ser | Published November 7 | | --- | --- | --- | NOTE Rafting by five phyla on man-made flotsam in the Southern Ocean David K. A. Barnes*, Keiron P. P. Fraser British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK ABSTRACT: In just 4 decades, marine litter has become abundant in northern oceans and seas and is increasing on even remote Southern Ocean island shores. The Southern Ocean was thought to be protected from rafting organisms by its freezing sea surface temperatures. Here we report on an assemblage of animals attached to a piece of plastic that was washed ashore on Adelaide Island, Antarctic Peninsula (68° S) . The band of plastic was positively buoyant. At least 10 species belonging to 5 phyla were present on the plastic and the size of some indicated that it had been afloat for more than a year. Clearly it is possible for a range of animals to survive and grow in such an environment, and so exotic species could enter or leave the Southern Ocean. KEY WORDS: Marine debris · Plastic · Invasive species · Antarctica ~~ ~~ Resale or republication not permitted without written consent of the publisher ~~ ~~ INTRODUCTION Over the past 4 decades there has been a massive invasion of floating plastic litter in the marine environment, with potentially significant consequences for the transport of invasive species. The only shores and sea surfaces free of persistent plastics were, until recently, at high, southern polar, latitudes (Gregory et al. 1984), where it was thought that the Polar Frontal Zone (PFZ) might act as a barrier to surface transport. However, driftwood and fishing-related castoff materials have now crossed the PFZ in both directions (Barber et al. 1959, Coombs & Landis 1966), which raises the possibility for transport of organisms into the Southern Ocean, the only marine realm for which no manmediated invaders are yet known. Floating at the surface and at the interface of variable air temperatures and freezing surface temperatures would seem likely to make it hard for animals to colonize this potential transport. Colonization of high latitude drift debris is very low (Barnes 2002) and no biota has been described from the many surveys of rubbish washing *[Email: dkab@bas.ac.uk](Email: dkab@bas.ac.uk) ashore on northern-most Antarctic islands (Gregory et al. 1984, Convey et al. 2002) . Here we describe the first report of persistant colonizers on floating plastic in the Southern Ocean. DEBRIS ANALYSIS In February 2003 we found and examined a piece of debris (only the 4th we know of in 5 yr) that was washed ashore on Adelaide Island, Antarctic Peninsula (68° S). This was a piece of plastic packaging band (Fig. 1) of the sort used extensively by Antarctic basesand fishing boats and has commonly been found entangling seals (Bonner & McCann 1982) . Placement of the band in the sea confirmed that it was positively buoyant. The fact that this plastic band was colonized is highly unusual—only rarely, and then at latitudes <60° S, have there been reports of anthropogenic debris in the Southern Ocean colonized by fauna. Such reports have only mentioned stalked (lepadomorph) barnacles (MacIntyre 1966, M. Schulz & H. Burton © Inter-Research 2003 · [www.int-res.com](www.int-res.com) unpubl.) . On this Antarctic debris we found 5 cheilostomatid bryozoans, 2 demosponges (Porifera), 2 polychaetes (Annelida), a hydroid (Cnidaria) and a small gastropod (Mollusca) . Colonization had taken place within the Southern Ocean, as the gastropod Laevilitorina antarctica and all 5 bryozoans (Aimulosia antarctica, Arachnopusia inchoata, Ellisina antarctica, Fenestrulina rugula and Micropora brevissima) present are endemic to the Southern Ocean. None have ever been described colonizing floating material before, and only 1, A. antarctica, has been found in the intertidal zone (Bar

FAQs

Why was the Southern Ocean considered protected from rafting organisms?

Freezing sea-surface temperatures were thought to hinder colonization and survival of animals rafting on floating debris.

What was found on the plastic debris washed ashore on Adelaide Island?

A positively buoyant plastic packaging band hosted multiple taxa, including bryozoans, demosponges, polychaetes, a hydroid, and a small gastropod.

What does the study suggest about animal transport between the Southern Ocean and other regions?

The presence of endemic Southern Ocean species on long-floating plastic indicates that such debris can carry diverse organisms, potentially allowing exotic species exchange into or out of the region.

Aug 28, 2026

Uploaded by Jacob